The effects of long-term starvation and acclimation temperature on glucose regulation and nitrogen anabolism in the frog, Rana pipiens—II. Summer animals

Abstract

1.1. Concentrations of serum glucose, serum amino acids and serum urea, as well as total excreted urea measured in frogs, Rana pipiens—obtained in early August—acclimated at 4 and 25°C, during food-deprivation lasting 14 and 8 days respectively.2.2. The concentrations of glucose, amino acids and urea in serum were maintained at 27·4 (hypoglycemic) and 40·0 mg%, 25·2 and 27·1 mM/1, and 3·61 and 10·34 mM/1, respectively, in 4 and 25°C acclimated R. pipiens.3.3. The rates of urea excretion were measured and observed to decrease during starvation, with mean values of 30·0 and 214· mμmoles urea excreted/g wet wt. per hr in 4 and 25°C acclimated frogs.4.4. Regulation of the concetration of glucose in serum was discussed with respect to amino acid primed gluconeogenesis and triglyceride storage.5.5. Based on these observations, it is suggested that triglycerides are the primary mobilizable metabolic storage products in summer R. pipiens.